IMPHAL, MANIPUR // Out on National Highway 39, deep in the forested hills of Manipur, a teenage boy and a middle-aged woman with a leather handbag over her shoulder are inspecting a passenger bus.
They are operating an illegal checkpoint. They look through the baggage compartment before climbing aboard to check under the seats and along the overhead racks. They are searching for anything that constitutes an import - whether it's a sack of potatoes, a bag of coal or a can of petrol. Satisfied that no contraband is on board, they wave the bus through.
At this time in the early afternoon, the checkpoint has a relaxed and informal air. No guns are waved at the drivers, no threats are made.
But the burnt-out remnants of lorries and jeeps that line the road on either side speak for themselves. "These things happen after dark," says one of the checkpoint volunteers with a grin.
For almost three months, a group of villagers in the Sardar Hills region of Manipur have been enforcing this blockade on one of the main supply routes into this small and isolated state. By choking off supplies, they hope to pressure the government into giving them their own administrative district, allowing them more control over development money and government contracts.
The effect of the blockade is immediately visible in the capital of Imphal, which lies in the valley below the hills. Motorists wait for hours at the few petrol stations that remain open. Prices for food and basic commodities have soared. Hospitals are even reporting shortages of essential medicines.
On the surface, the reason for the blockade sounds prosaic, but it is tied up with the long-running and often violent animosity between the two tribes that dominate these hills - the Kukis and the Nagas - as well as demands for self-determination that date back to the birth of independent India.
In the 1990s, bitter ethnic clashes between the Kukis and Nagas left nearly 1,000 people dead and hundreds of homes burnt to the ground. The violence was fuelled by the presence of dozens of armed groups keen to wrest control of the drug-smuggling routes that run across the border into Myanmar.
Today, the intertribal killings have ceased, but the Kukis say the local government offices are still dominated by the Nagas, who siphon off the majority of the money for themselves.
"We are not demanding this [an independent district] just for the Kukis," said SH Seipu, a community leader in the Sardar Hills. "It is for every community that lives in this region. At the moment, 80 per cent of education grants, employment schemes and recruitment drives go to the Nagas living around the district headquarters. This has to change."
The Nagas see things differently. For them, the entirety of these hills are part of their ancestral homeland, and the Kukis, who migrated here mostly over the last 200 years, are recent interlopers.
"We cannot drive the Kukis away, but they should acknowledge our ownership of this land," said Lohrii Adani, president of the United Naga Council, based in Senapati.
"We are not against the formation of a new district in Sardar Hills per se, but there are many Nagas living in that region and we are against any agreement that divides our community."
Soon after the Kukis started their blockade in August, the Nagas set up their own counter-blockade on the other major motorway into Manipur. They established the blockade to oppose the district the Kukis are demanding.
Both say they have the law on their side, and brandish memoranda from the state government dating back 40 years in which various, contradictory promises have been made.
In the background are dozens of insurgent groups - at least 40 by some counts. Many want independence for their respective communities, and use this as a cover for continuing to extort taxes and intimidate local businesses, leaving little room for moderate voices to prevail.
"There doesn't seem to be any room for negotiation," said Pradip Phanjoubam, editor of the Imphal Free Press.
"The local politicians are doing very well out of these blockades - they can jump on the bandwagon of either side to generate public support, but if it doesn't end soon, it could quickly descend into violence."
Already, four deaths have been linked to blockade-related violence, although the details remain unclear. After the death of a driver in September, transport unions organised a strike that further crippled supplies to the state.
Aware that arrests could spark more violent protests, and with one eye on local elections next year, the government has allowed the blockades to continue, while providing security for occasional emergency supplies to get through.
But many see a wider political game being played, since the current agitations come at a sensitive time for talks between Naga insurgents and the central government in New Delhi.
Naga militants - not only in Manipur, but across the Indian north-east and into Myanmar - have been demanding their own independent country for more than 60 years, making it the longest-running insurgency in India.
A ceasefire has tentatively held since 1997 with the leading insurgent organisation, a faction of the National Socialist Council of Nagaland, although occasional terrorist attacks and killings continue.
Reports suggest their talks with the government in New Delhi may be about to bear fruit.
"We are told they are close to an agreement based on the idea of shared sovereignty," said Mr Adani. "We still want full independence, but a compromise may be the best option for our people."
A final agreement on the Naga question would not be welcome by many Manipuris, who fear the break-up of their state. Manipur was an independent monarchy for some 2,000 years before its annexation into India in 1947.
As if the situation were not complicated enough, the native Manipuris, or Meiteis, have their own insurgent groups demanding independence from India, as do the Kukis.
Many believe the state government and these competing insurgent groups may be quietly supporting the recent Sardar Hills agitation as a way of undermining the Naga's desire for their own state.
"This could all be a negotiating tactic by the government," said Jitan Yumnan, a local human-rights activist. "They know that granting the Sardar Hills would make it harder for the Nagas to claim this whole area as their land."
Mr Adani agreed: "It's the old tactics of divide and rule, and they have an old wound to play on."
In the murky world of northeastern politics, where militancy, political intrigue and the threat of ethnic violence have formed a perpetual backdrop to daily life for decades, it is hard to know where genuine negotiations start and conspiracy ends.
"The government is using money and power to manipulate and divide communities," Mr Yumnan added.
"They support one group against the other, making the issues more and more complicated, while doing nothing to deal with the real economic needs of the people.
"If they don't handle this situation carefully, we could see a return to the violence of the 1990s."